1. Field of the Invention
The present invention relates to an elevator control system adopting a group management system, and more particularly to an improved communication apparatus for an elevator control system capable of allowing a communication relay system responsible for a signal reception/transmission between a plurality of car controllers or a group management controller and a plurality of hall terminals to independently process data signals outputted from the hall terminals.
2. Description of the Background Art
FIG. 1 is a block diagram illustrating a conventional communication apparatus for an elevator control system. As shown therein, the communication apparatus includes: a plurality of car controllers 11A-11N for controlling respective operations of a plurality of elevator cars; a group management controller 12 for carrying out a common operation with regard to the plurality of elevator cars; a plurality of hall terminals 14A-14N, 15A-15N for controlling an input/output with regard to a plurality of present running floor display devices, hall call button units, arrival notice units and the like, and being disposed at floor halls with the number corresponding to the hall call buttons; and a communication relay system 13 for relaying data between the car controllers 11A-11N and the group management controller 12 and the hall terminals 14A-14N, 15A-15N via a group network GNW and a hall network HNW. Therein, the group network GNW and the hall network HNW respectively denote a common serial transmission line, and the hall terminals 14A-14N, 15A-15N are selectively disposed in each floor by the number thereof corresponding to the hall call buttons.
Here, present running floor display devices which are not drawn in FIG. 1 respectively serve to display a present running floor of an elevator car. The hall call button unit outputs a signal corresponding to a hall call in accordance with a passenger's call. The arrival notice unit displays a moving direction of an elevator car. And each of the present running floor display devices, the hall call button units, and the arrival notice units are disposed at each floor hall.
For instance, when a ten-story building is provided with four elevator cars and two hall call button units on each floor thereof, there are required twenty hall terminals. On the top and ground floor halls there are respectively provided one hall call button unit, and on each of the rest floors there are provided two hall button units; one at a top portion, the other at a bottom portion, on the respective floors between the ground and the top floor.
The operation of the thusly constituted conventional communication apparatus for an elevator control system will now be described.
Each of the hall terminals 14A-14N, 15A-15N respectively disposed at a corresponding floor hall receives signals from a present running floor display device, a hall call button unit, an arrival notice unit, and transmits the received signals through a hall network HNW serving as a common serial communication line to the communication relay system 13. The communication relay system 13 determines which floor the received signals are from (for example, input signals from a third floor of a first row), and which signals they are (for example, whether the elevator car call is for normal or disabled passengers or for VIPs, or the received signals are from a hall terminal number setting switch), whereby the resultant signals are transmitted through the group network GNW serving as a common serial communication line to the group management controller 12.
If the received signals are relevant to a car call, the group management controller 12 selects an appropriate car and allocates the car call to the car controllers 11A-11N which control the selected car. If the received signals are related to a car running pattern, a corresponding control command is transmitted to the respective car controllers 11A-11N. The communication between the group management controller 12 and the car controllers 11A-11N is carried out by use of a serial communication method through the group network GNW.
Also, the signals applied from the car controllers 11A-11N or the group management controller 12 to the hall terminals 14A-14N, 15A-15N are serially transmitted through the group network GNW to the communication relay system 13. The output data of the communication relay system 13 are serially transmitted through the hall network HNW to the hall terminals 14A-14N, 15A-15N. Here, if the received data are relevant to the hall terminals 14A-14N, 15A-15N themselves, they are appropriately processed and sent to corresponding appliances.
The thusly obtained data may vary to an answering signal (call register signal) to the hall call, a direction signal for notifying a car running direction, and a present location display signal of the elevator car.
Meanwhile, in the case there is provided a system in which the plurality of car controllers 11A-11N and the group management controller 12 are connected to the single common serial transmission line GNW, and the hall terminals 14A-14N, 15A-15N are connected to the single common serial transmission line HNW, the more floors a building has, the more frequently there occurs an increased communication charge rate, a communication congestion or a communication data collision, thereby deteriorating a system efficiency thereof. Although those disadvantages may be overcome to a certain extent by the so far proposed relevant arts, there still remain problems as follows.
First, in order to determine which hall terminal the signals applied to the communication relay system 13 are from, the respective hall terminals 14A-14N, 15A-15N should be assigned identification numbers ID, and switching devices for setting the identification number ID serving as a code that discerns the hall terminals 14A-14N, 15A-15N should be provided in the respective hall terminals 14A-14N, 15A-15N. Here, the entire hall terminals 14A-14N, 15A-15N are connected to the hall network HNW serving as the single common serial communication line so that there should be respectively determined which floor and which hall button unit the respective hall terminals 14A-14N, 15A-15N are disposed for, thereby further complicating an installation thereof.
Secondly, there is a disadvantage relevant to a communication charge rate for the single common serial transmission line HNW which serves to couple the respective hall terminals 14A-14N, 15A-15N with the communication relay system 13. The more cars and floors in a building, the more hall call buttons there should be provided accordingly, whereby the thusly congested communication load may result in collisions between communication data.
Thirdly, a breakdown of the communication relay system 13 may damage the reliability of the system. When the communication relay system 13 is provided with a single CPU, any erroneous operations of the CPU or breakdowns of the communication relay system 13 may result in a communication path interruption with regard to the hall terminals 14A-14N, 15A-15N, thereby disabling hall call data reception and accordingly damaging the system reliability.
Fourthly, there comes a supply power with regard to the communication relay system 13 and the hall terminals 14A-14N, 15A-15N. When supply power required for the communication relay system 13 and the respective hall terminals 14A-14N, 15A-15N is supplied from either of the group management controller 12 and the respective car controllers 11A-11N, and when there occurs an error to the supply power that is to be provided to the group management controller 12 or the respective car controllers 11A-11N, the communication relay system 13 becomes disabled. Accordingly, although other controllers are operating normally input signals of the respective halls are not received via the communication relay system 13. In order to overcome this disadvantage, there may be provided relays or contactors in the group management controller 12 and the respective car controllers 11A-11N, and respective contact nodes between the relays and the contractors may be combined with each other. Here, if there does not occur a simultaneous error with regard to the entire control devices, power becomes supplied to the communication relay system 13 and the hall terminals 14A-14N, 15A-15N by use of a selected control device. However, in this case, the combination in the contact nodes tends to be complicated and each control device should be provided with a required capacity of supply power, thereby incurring otherwise unnecessary cost.
That is, the supply power outputted from the car controllers 11A-11N is supplied to the communication relay system 13 and the hall terminals 14A-14N, 15A-15N, so that there may occur an error to the power devices of the car controllers. Also, by turning off a main power breaker which is provided in the car controllers 11A-11N for the purpose of maintenance/checkup, the supply power to the communication relay system 13 or the hall terminals 14A-14N, 15A-15N may be turned off, thereby failing transmission of input signals generated in the halls.
As described above, in a communication apparatus for an elevator control system, there have yet to be solved such problems as a communication charge rate with regard to a hall network, a reliability of the system which is provided for the communication relay system, an identification number allocation method for discerning installation locations of the respective hall terminals, and a power supply to the communication relay system and the plurality of hall terminals.